Flashbulb with percussion ignition and pre-formed ignition tube

ABSTRACT

AN IGNITION TUBE WITH ONE END SEALED INTO A FLASHBULB AND ITS OTHER END PROJECTING EXTERNALLY OF THE BULB IS FILLED WITH FLASH MATERIAL (SUCH AS SHREDDED ZIRCONIUM FOIL). THE END OF THE IGNITION TUBE PROJECTING EXTERNALLY OF THE BULB IS PRE-FORMED IN A SPECIFIED REGION AND SHAPED TO HAVE A RECTANGULAR OR SIMILAR CROSS-SECTION SO THAT IT HAS ONE LONG AND ONE SHORT CROSS SECTIONAL DIMENSION, TO AVOID THE NECESSITY OF SUBSTANTIAL DEFORMATION UPON BEING STRUCK AN IGNITION BLOW, THE PERCUSSIVE TYPE IGNITION MATERIAL IS LOCATED, AT LEAST PARTLY, IN THE DEFORMED REGION, PREFERABLY ENCAPSULATED AS A SEPARATE STRUCTURAL ELEMENT.

June 20, 1972 w. SCHILLING ETA!- 3,671,166

FLASHBLUB WITH PERCUSSION IGNITION AND PRE-FORMED IGNITION TUBE 2Sheets-Sheet 1 Filed July 30, 1970 zone C zone b ZONE a Werner SchillingWolfgang Ott INVENTORS fir q fi BY ATTORNEY$ June 20, 1972 w. SCHILLINGE 3,671,166

FLASHBLUB WITH PERCUSSION IGNITION AND PRE-FORMED IGNITION TUBE 2Sheets-Sheet 2 Filed July 30, 1970 ZONE a FlGA FIG. 3

zone a FlG.7

FIG. 6

Werner Schilling Wolfgang Ott INVENTORS V? 3&7 ATTORN EYS United StatesPatent 3,671,166 FLASHBULB WITH PERCUSSION IGNITION AND PRE-FORMEDIGNITION TUBE Werner Schilling, Heidenheim, and Wolfgang Ott, Augs burg,Germany, assiguors to Patent-Treuhand-Gesellschaft fur elektrischeGluhlampen mbH, Munich, Germany Filed July 30, 1970, Ser. No. 59,517Claims priority, application Germany, July 31, 1969, P 19 39 085.3 Int.Cl. F21k /02 US. Cl. 431-93 11 Claims ABSTRACT OF THE DISCLOSURE Anignition tube with one end sealed into a fiashbulb and its other endprojecting externally of the bulb is filled with flash material (such asshredded zirconium foil). The end of the ignition tube projectingexternally of the bulb is pre-formed in a specified region and shaped tohave a rectangular or similar cross-section so that it has one long andone short cross sectional dimension, to avoid the necessity ofsubstantial deformation upon being struck an ignition blow; thepercussive type ignition material is located, at least partly, in thedeformed region, preferably encapsulated as a separate structuralelement.

CROSS REFERENCE TO RELATED APPLICATION US. application Ser. No. 838,758,filed July 3, 1969, now patent No. 3,624,824, and US. Ser. No. 59,581,filed July 30, 1970.

The present invention relates to fiashbulbs which are ignited by apercussive ignition mixture, in which combustible flash material islocated in a bulb, together with a combustion supporting substance suchas oxygen. A small metallic tube is sealed into the bulb, incommunication with the interior of the bulb, and containspercussion-sensitive material to ignite the actual flash material withinthe bulb.

Percussively ignited bulbs are flashed by applying an impact, such ahammer blow to the side of the metal tube, for convenience hereinafterreferred to as the ignition tube. Preferably, the blow is provided by apair of counteracting hammers, swinging in a direction perpendicular tothe axis of the ignition tube, to avoid unbalance and possible blurringof a photographic picture to be taken. The blow against the ignitiontube causes deformation thereof. The blow damages the tube and requiresa certain amount of force.

It is an object of the present invention to improve lamps of thepercussive-ignition type by reducing the required impact to ignite thetube and to reduce the danger of destruction of the ignition tube.

SUBJECT MATTER OF THE PRESENT INVENTION Briefiy, the ignition tube ispre-formed in a specified region beyond its seal to the bulb, and shapedsuch that the cross-section has a smaller and a larger diameter, forexample, to be in rectangular, or similar form. Predeformation of thetube, so that one diameter is less than the other decreases the amountof force required to ignite the percussive material, and avoids thenecessity of a substantial deformation of the tube by the percussionhammer during ignition, itself; while, simultaneously, providing for asuitable location and attachment of the percussive ignition materialwithin the interior of the tube.

The impact energy required to ignite the percussive material is lessthan the impact force required for a cylindrical tube, since thedistance of the wall surfaces of the tube, in the pre-deformed region isalready substantially decreased. Decrease of the required impact energydecreases the probability of blurred images due to camera movement.Additionally, the ignition tube, which is frequently closed by coldpress welding is less likely to tear during ignition of the percussivematerial, which results usually in incomplete combustion of thecombustible material within the bulb and blackening thereof.

The invention will be described by way of example with reference to theaccompanying drawings, wherein:

FIG. 1 is a schematic longitudinal sectional view through a fiashbulb;

FIG. la is a detail view of the ignition tube;

FIG. 2 is a top, cross-sectional view of a percussion cap, i.e. a fireloaf;

FIG. 2a is a longitudinal side view of the percussion cap of FIG. 2;

FIG. 3 is a fragmentary cross-sectional view of the ignition tube inlongitudinal section;

FIG. 4 is a different embodiment of the invention, similar to FIG. 3;

FIG. 5 is a longitudinal cross-sectional view of the ignition tubehaving a percussion cap, i.e. a fire loaf and a carrier;

FIG. 6 is a longitudinal cross-sectional view of the ignition tube withan ignition cap and a carrier, which serves as an anvil; and

FIG. 7 is a longitudinal sectional view of an ignition tube with acarrier partly having percussive material applied thereto.

The fiashbulb (FIG. 1) has a light transparent tubular bulb 1 filledwith a combustible material 2, for example, shredded zirconium foil, andoxygen of approximately 7 atm. The tube may be sealed by any convenientmeans, for example, by a metal exhaust tube 3, for example, of copper,sealed off after evacuation and filling of the lamp. The other end ofthe bulb 1 has a small metal tube 4, preferably also of copper, sealedinto the bulb 1 which is cylindrical in the region extending within thebulb. The region A just beyond the bulb is likewise cylindrical; thenext adjacent region, B, however, is pre-deformed by being squeezed orpressed togethcrsee FIG. la. The metal tube 4, which forms the ignitiontube is so pre-deformed that two wall sections 4a result, locatedopposite each other, defining an acute angle and substantially fiat,pressed together along zone a of section B with such pressure that, bycold-press welding, a vacuum tight, pressure resistant end closure ofthe tube 4 is formed. Additionally, the press may be soldered. Zone I:of the section B includes ignition material 6 which extends over and upto zone 0 of the section B. The ignition material may, for example, be amixture of powdered zirconium, potassium chlorate, red phosphorus,aluminum oxide and binder.

The ignition material itself, for example, has the form of a center bitm of an ignition cap 7, known as a fire loaf, such as used, for example,in toy guns, cap pistols and the like. Such ignition caps, i.e. fireloafs are formed of two adhered paper layers, usually colored red,between which a mixture of red phosphorus and potassium chloride, mixedwith gum arabic is located. The center bit 221 of such fire loafscontains approximately half of the amount of percussive ignitionmaterial as that used in toy pistol caps, that is approximately 0.5 to 3mg. Such a cap may be held by being squeezed between the two wallsections 4a in the zone 11; approximately 1 to 2 mm. extending free intothe zone c of the section B. Thus, an ignition spark caused by impactagainst the tube 4 can freely expand into the interior of the bulb, tostart ignition of the combustible material therein; alternatively. andas shown in FIG. 1, the pressure wave caused by ignition of cap 7 cancause an additional primer bead to ignite which, in turn, causesignition of the combustible material Within the interior of the bulb.The primer bead 5 is frequently not necessary since combustion of theflash-generating material within the bulb 1 can frequently be starteddirectly by the cap 7.

The invention can be used with percussive ignition material insertedinto the tube in various ways. FIG. 3 illustrates section B of theignition tube 4 which particularly in the zone b is filled with powderedpercussive ignition material, closed off by means of a stopper 8, forexample, made of metal or plastics. Upon deformation of the ignitiontube, for example, by an impact in the direction of the arrows thestopper is ejected by the pressure of the ignition into the interior ofthe lamp to enable the ignition spark to spread.

Embodiment of FIG. 4: The ignition material is located within anencapsulating housing to form a cap -9 which tears upon ignition of thepercussive material. The cap 9 can be made of metal, such as copper,thermoplastic material, paper or other suitable substances. The cap 9 islocated between the flat wall sections 4a, by being pinchedtherebetween, and located in the zone b, and extends clear into the zonec. Ignition of the lamp is initiated by a short impact in the directionof the arrows (FIGS. 1, 3, 4) by means of a hammer mechanism, preferablya dual hammer mechanism acting on both flat wall sections of tube 4within the section b, and preferably against the center of the ignitionmaterial.

Embodiment of FIGS. 5 to 7: The center bit m of a fire loaf (FIG. 5) anignition capsule 9 (FIG. 6) or an ignition mass 12 (FIG. 7) is locatedon a carrier 10 which may, for example, be a small plate of hardmaterial such as steel. The ignition material, that is the fire loaf orcapsule, or the like may be adhered to the carrier plate 10. Theignition mass 12 may be covered with a foil 13 such as paper, cardboard,thermoplastic material or the like. The carrier can be formed with aplastic ring 11 and it is frictionally held by the squeezed-togetherwall sections 4a. The carrier plate 10 forms a support which has thefunction of an anvil, thus providing for reliable ignition even withsmall percussive energy. According to the embodiments of 'FIGS. 5 to 7,the percussive energy can be applied by a single-sided blow by means ofa hammer mechanism, as indicated in FIGS. 5 to 7 by the arrow. Theimpact is directed solely to the flat wall section 4a of the metal tube4 which is immediately adjacent the ignition material.

During manufacture of flashbulbs of the present invention, it ispreferred to insert the ignition material in the form of small caps,(fire loafs), capsules or carriers with ignition material in any form,for example, either from below through the metallic tube 4 and thenslowly squeezing the tube together. Alternatively, the ignitionmaterial, for example, in powdered state may be filled into an alreadyclosed metal tube from a direction of the interior of the lamp.

The present invention has been illustrated and described particularly inconnection with small photographic-type fiashbulbs; various changes andmodifications may be made within the scope of the inventive concept tomeet design requirements.

We claim:

'1. 'Flashbulb having a transparent bulb containing combustible materialand a combustion supporting substance a tubular extension of deformablematerial projecting from said bulb, forming an ignition tube, extendinginto said bulb and being sealed thereto, the ignition tube beingunobstructedly open at its inner end which extends into the bulb andbeing closed at the other end;

the tube being flattened and pre-deformed in the projecting region tohave a shape such that its crosssection has a dimension which issubstantially less than the diameter of the tube at its seal to the bulbto avoid substantial deformation upon percussion against the tube;

and percussive type ignition material contained within the tube andlocated at least partly within the flattened pre-deformed region. I

2. Flashbulb according to claim 1, wherein said ignition tube is ofmetal.

3. Flashbulb according to claim 1, wherein the ignition tube has a firstportion (A) adjacent the bulb which is cylindrical in cross section;

and a second next adjacent portion (B) which is squeezed out-of-round tobe flattened and to form a. pair of opposite wall sections which,between themselves, define a small acute angle;

and said percussive type material is located in said second section.

4. Flashbulb according to claim 3, wherein;

a stopper is provided closing off the tube containing the percussivematerial towards the bulb.

5. Flashbulb according to claim 3, wherein the percussive material isenclosed in a cap and said cap is pinched between the wall sections.

6. Flashbulb according to claim 3, wherein the percussive material hasthe form of a center bit (m) of an ignition cap, forming a fire loaf.

7. Flashbulb according to claim 3, wherein the percussive material isencapsulated in a plastic cap.

8. Flashbulb according to claim 3, wherein the percussive material isencapsulated in a metal cap.

9. Flashbulb according to claim 3 including a support carrier, saidpercussive material being applied to said support carrier.

10. 'Flashbulb according to claim 9, including a ring of thermoplasticmaterial securing said support carrier within said pre-deformed region.

11. Flashbulb according to claim 9, wherein the support carrier ispinched between the acute angle formed by said flattened opposed wallsections.

References Cited UNITED STATES PATENTS 3,521,984 7/1970 Fink 431-933,535,063 10/1970 Anderson 43193 2,998,777 9/1961 Ryan 10286.5 3,363,5631/1968 Eckstein 10286.5 X 3,499,386 3/1970 -Stadler 102-865 FOREIGNPATENTS 465,021 4/1937 Great Britain 43 l95 EDWARD .1. MICHAEL, PrimaryExaminer

